Steam ejector with cooled diffuser



2 Sheets-Sheet 1 March 17, 1925. v

A. DELAS STEAM EJECTOR WITH COOLED`DIFFUSER- Original Filed Oct. 19,1920 f/Z 1 l EE March '17, 1925. 1,529,774

A. DELAS STEAM EJEGTOR WITH COOLED DIFFUSER original Filed oct. 19, 19202 Sheets-sheet 2 i l l Patented Mar. 17, 1925.

UNITED STATES PATENT OFFICE.

ALBERT DELAS, OF PARIS, FRANCE, ASSIGNOR T DELAS CONDENSER CORPORATION,

OF NEW YORK, N. Y., A CORPORATION 0F DELAVARE.

STEAM EJECTOR WITH COOLED DIFFUSER.

Application led October 19, 1920, Serial No. 417,989. Renewed August 4,1924.

To aZZ whom t may concern:

Be it known that I, ALBERT DELAS, a citizen of the Republic of France,residing at Paris, France, have invented certain new and usefulImprovements in Steam Ejectors with Cooled Diffusers, of which thefollowing is a full, clear, and exact description.

The invention which constitutes the subject matter of this applicationrelates to ejectors, and has for its object to effect certainimprovements in the construction and method of operation of ejectors ofthe type disclosed in my Patents No. 1,374,990, April 19, 1921, and Nos.1,499,349 and 1,499,350, July 1, 1924, and my copending application Ser.No. 260,6011/2, iiled Oct. 31, 1918.

In my above mentioned prior applications I have pointed out certainnovel important results obtained by circulating cooling fluid around thewalls of the converging portion of the diffuser and further advantagesand important results obtained by also cooling the neck and outletportions of the diffuser. Stated somewhat generally, such coolingincreases both the efficiency and stability of operation of ejectors. Apreferred form of such ejector comprises a diffuser provided with aconverging inlet portion, a substantially cylindrical neck portion, asubstantially cylindrical outlet portion and with means for circulatinga cooling fluid around the exterior of the walls of the said inlet, neckand outlet portions of the diffuser.

In order to enhance the cooling effect, the walls of the diffuser shouldbe made thin and out of good heat conductivity. During the operation,the diffuser is subjected to wide fluctuations of temperature,especially when steam is passing through the diffuser, and, throughaccident or mistake, the circulation of the cooling fluid is stopped.Under such circumstances the diuser may reach a temperature higher thanthat of its enclosing casing, and in the absence of special provisionswould be subjected to strains and consequent buckling or otherdeformation. In my prior applications I have disclosed arrangements inwhich the diffuser is provided with an expansion joint at, at least, oneend thereof to permit expansion and contraction of .the diffuser withrespect to the remaining structures. If sea water is to be employed asthe cooling Huid it is important that the expansion-permitting-means beso tight that entrance thereof into the diffuser or path of the motiveand entrained iiuid is prevented, especially when the lat ter mixture isto be condensed and the fluid of condensation eventually returned to theboilers.

One of the objects of the present invention is to provideexpansion-permitting-means meeting the above stated requirements withoutsacrificing the solidarity and simplicity of the general structure.

In my said prior applications I have disclosed arrangements in which thediusers are surrounded by sleeves in comparatively close proximity tothe same and between which dilfusers and sleeves the cooling Huid iscaused to flow. By virtue of this arrangement a maximum cooling effectis obtained for a given quantity of cooling iiuid. Ihave discovered thatit is especially important that the wall of the neck of the twodiffusers should be maintained at a low temperature.

Another object of the invention is to provide an arrangement and methodfor intensively cooling the di'user neck portion. 80

A further object of the invention is to provide a reservoir or storagechamber for the cooling fluid adjacent and surrounding the diffuser sothat in case of cessation of circulation of said fluid the otherwiseincidental rise in temperature of the diffuser walls is prevented. Otherobjects and advantages will appear as the invention is hereinafterdisclosed.

Referring to the drawings which illustrate what I now consider preferredforms of apparatus embodying my invention:

Fig. 1 is a sectional elevation of a single stage ejector embodyingcertain features of the invention.

F ig. 2 is a view similar to Fig. 1, but illustrating an additionalfeature of invention. f

Figs. 3 and 4c are views similar to 2, but illustrating modifications.

Fig. 5 is a sectional elevation of a two stage ejector system embodyingcertain features of the invention.

Fig. 6 is a sectional elevation of a two stage ejector system in whichthe two ejectors are arranged side by side instead of in axialalignment, as in Fig. 5.

Fig. 7 is asectiontalren on the line A-B of Fig. 6.

fFig. 8 is a view similar to Fig.l 6, but illustrating certainmodifications.

Fig. 9 isa view similar to Fig. 8, but illus.'- trating furthermodifications.

Fig. 10 is a section on the line A-B oi Fig. 9.

Figs. 11. and illustrating certain features of the various forms of theinvention.

Referring to Fig. 17 it will be seen that the ejector there illust 1atedcomprises an enclosing casing 1 provided with a nozzle 2 adapted to besuppliedwith steam or other elastic motive fluidunder pressure and todischarge the same into the chamber 8i. The latter is adapted tocommunicate at l with the source of fluid,V such `as air, vapor, steamormixture of' the same, whose pressureis to be raised .in the ejector.vSuitably secured within the casing 1 is a. tubular diffuser 5 throughwhich the mixture ofniotive fluid and entrained Huid passes. I haveillustrated my preferred form of diffuser, which comprises a converginginlet portion 6, a substantially cylindrical neclr .portion 7 and asubstantially cylindrical outlet portion 8. Tater orA other coolingfluid is introduced through the opening 9 into the.. annular chamber 10,bounded bythe casing 1 and a cylindrical portion y11 of a sleeve member12 suitably secured within thecasing and surrounding the upper endof thediffuser 5. The member 12 terminates at its lower portion in .a tubewhich, speakingrgenerally, conforms. to the shape of the exterior of'the diffuser. It will be noted Athat the member 12 is constricted nearthe necl of the dii'- 'l'useiz The ycylindrical portion 11 is providedwith a peripheral row or series of holes 13 through which the coolingfluid flows from the annular chamber 10 into the space between thesleeve 12andY the exterior of' the diffuser 5. The sleeve. 12 dischargesinto a reservoir orstorage chamber le p`rovided in the casing 1 andsurrounding the .sleeve and diffuser. The cooling fluid leaves :thechamber 14- through the hole or aperture 15 provided ,in the casing 1:adjacent the top .of the chamber 14h lt will be understood by vthoseskilled in the art that steam issuing from the nozzle 2 will entrain theair and vapor or other lfluid in the chamber 3 and impart velocitythereto. The mixture of motive and eu.- trained fluids then passes`through the diff .fuser 5 when, by rconversion of velocity lintopressure, its pressure is raised. Tater o1' other cooling fluid issupplied from anysuit7 able source and flows as follows: Entering at theaperture 9 the cooling fluid flows 12 are enlarged detail viewsK aroundthe chamber 10 and through the holes 13A into the space between sleeve12 and diffuser 5. It will be appreciated that the cooling fluid isspread evenly around the diii'user by'virtue of the construction abovedescribed. The cooling fluid then flows downwardly in the sleeve 12 andaround the exterior of the walls of the difi'user 5 cooling the same.rlhe device is thereby rendered highly stable and efhcient in itsoperation. The cooling fluid flows from the sleeve 12 into the chamber14: and out at exit 15. Even though the circulation should cease for anyreason during the operation of the ejector the diffuser walls wouldnevertheless be maintained at a comparatively lowv temperature by thelarge mass oil' fluid in the storage cham-ber 14.

ds previously stated, it is important that the neck of the diffuserbemaintained at a low temperature. By virtue of the constriction of thesleeve i2 the velocity of the stream of cooling fluid is raised at andadjacent they constricted section so that the wall of the neck portionof the diffuser is intensively cooled.

For reasons hereinbefore stated, l prefer to provide the diffuser 5 with`expansionpe1init'tinLG-ineans which may assume various forms. line form.is illustrated in Fig. 2 and may be constructed substantiallyasfollows: y

The diffuser 5i is fnredly secured at. its upper end with respect to thecasing 1, but its outlet end 8 passes through a stuffingbox 16. Thelatter comprises a gland portion secured to the |casing 1 and in whichthe packing is held by a nut or locking ring 17. Obviously afluid-tight, diflusenexpansionprmitting joint is provided by thestructure described, and interminglingof the cooling fluid and ejectedfluid is prevented.

A different form of expansion joint is illustrated in Figs. 2l and 11and may be conf structed substantially follows: rlhe lower end 8 of thediffuser 5- has secured thereto an externally threaded annular member orscrew18 provided with anut 19. il. centrally a-pertured undulated orcorrugated disc .or diaphragm 2G of metal or other suit able material issecured between the meinbers 18 and 19. The outer edge ofthe said disc20 is secured between the. casing 1 and a nut 21 cooperating therewith`as 'clearly indicated in Fig. 11. A. fluid-tight butdiffuser-erpansioiipei-initting joint between thediiifuser and casing 1is thereby secured.

ln both of the forms of invention illustrated in Figs. 2 and 3 thediffuser is placed in position by inserting the same downwardly into thecasing 1 andsubsequently, in the form shown in Fig. 27 tightening thenut 17 of the stuffing box or, .in the case of the form shownin Figs. 3and 11., tighteningthenut 19. The nuts 19 and 2l. may

be provided with notches 22 to effect their rotation. l prefer also toprovide the lower extremity of the diffuser and member 18 with notches23, one of which is shown in Fig. 11, whereby the diffuser and member 18may be held against rotation while the nut 19 is being turned, therebypreventing any torsional strains either on the diffuser or the ointbetween the same and said member 18.

In the form of invention shown in Figs. L and 12 the lower end of thediffuser is fixed and the upper end permitted to move with respect tothe casing. The lower end 8 of the diffuser has secured thereto anexternally threaded member 24 adapted to screw into the casing 1 thusconstituting a fixed joint. The upper part of the diffuser is providedwith an undulated or corrugated portion 27, whereby the diffuseiI may beelastically or yieldingly connected to the casing. The member' may beprovided with notches 28 for turning the same. ln order to preventtorsional strain between the diffuser and member 24 during the turningof the latter notches 29 are preferably provided in the lower end of thediffuser'. By inserting the wrench or other tool in both notches 28 and29 the diffuser and member 24C will turn as a unit and all tendencytoward relative rotation of these members is avoided.

l have described above some of the pre ferred forms of fluid-tightexpansion joints which may be employed and have thus far describedcertain features of the invention as applied to single stage ejectors.The invention may also be applied to multistage ejectors, as willhereinafter appear.

In Fig. 5 l have shown a two stage ejector in which the two ejectors areaxially arranged and connected in series to act on the elastic fluidwhose pressure is to be raised. ln view of the similarity between thetwo ejectors and the one shown in Fig. 1 no detailed description isnecessary. Sufiice it to say that the second stage ejector has certainof its parts, which correspond to the parts of the first stage ejector,designated by the same reference numerals with an added prime. In thisform of the invention the water or other cooling fluid enters at9,leaves the first stage at 15, passes through the pipe 30 into thesecond stage at 9' and leaves at 15. It will be noted that the waterpasses around the first` stage diffuser first rather than through thesecond stage first because water as cold as possible should be employedin the first stage where the pressure is lowest.

llhile the arrangement of ejectors shown in Fig. 5 possesses manydesirable features, it is disadvantageous to a certain extent, in thatthe steam or motive fluid nozzle 2', of the second stage ejector, and aportion of its supply pipe are located directly in the path ofthemixture of motive and entrained fluid dischai ged from the first stageand entrained in the second stage, giving rise to an objectionalelevation in temperature of the last mentioned fluid. `rin arrange-mentfor overcoming this objection is illustrated in Figs. 6 and 7 of whichmany of the illustrated parts will be recognized in view of thepreceding description.

In Figs. 6 and 7 the ejectors of the two stages are placed side by side,the first stage ejector discharging its mixture of motive and entrainedfluids into the second stage chamber 8 through a pipe 31. lWhile thewater or other diffuser-cooling fluid may be passed through the twostages successively, as shown in Fig. 5, is possible. and in somerespects preferable, to pass this cooling fluid through the two stagesin parallel. In this arrangement the water entering the cooling spacesof both stages is cold, as that entering the second stage has not beenheated by first passing through the first stage. The surface of bothdiffusers is maintained as cold as possible which is highlyadvantageous. One arrangement whereby the last described circulation ofthe cooling fluid may be secured is shown in Figs. 6 and '7, and may bedescribed as follows:

The water or cooling fluid is introduced at 9, and spreads in theannular chamber 10 of the first stage ejector where it. divides. Aportion flows through the first stage between the sleeve 12 anddiffuser' 5 while another portion flows through the channel 32 into theannular chamber 10 of the second stage. The passage of the cooling fluidthrough each stage will be understood in view of the precedingdescription. rlhe cooling fluid discharged from the rst stage at 15passes through a channel or passage 33 into the storage space 1d of thesecond stage which discharges through the exit opening 15.

In multi-stage. ejector systems it is quite often desirable to employ aninterstage jet condenser. When the water employed for cooling is pure(not salt water), or when the fluid discharged from the ejectors is notto be returned to boilers, the water supplied to interstage condensersmay be tapped from the water of the diffuserfcooling system. A suitablearrangement whereby this may be accomplished is illustrated in Fig. 8,and may be constructed substantially as follows;

Calling attention to the last mentioned figure, it will be seen that theoutlet 8 of the first stage diffuser 5 has attached thereto a bell 34provided with holes or perforations 35 through which a part of thecooling fluid in the chamber 14 enters to condense the steam or othercondensible fluid discharged from the first stage. The condensed fluidis withdrawn or leaves at 36 while the gaseous or elastic fluid passesto the second stage through the channel or passage 38 isto be employedtoaugmentl and heat thev boiler feed' Water, the form of' linventionillustrated in lFig. 8 is not desirable,f;as the;

cooling fluid is impure. The form of inven-4 tion shown in Figs. 9 andl0 may then be employed.

In thisI form of the invention the :bell-p34:- is connected to the`outlet 8 ofk they dilfuser. by a fluid tight joint and the upper Vpartof said bell is located in a chamber, 39 adapted to be supplied at 4L()`With water or condensing fluid from any suitable source, such as amaincondenser (not shown). In certain cases the Water from the maincondenser, a part of which is injected into the interstage condenser tocondense the steam issu-r ing from the first stage, 1s too Warm to beVemployed for cooling-.the diffuser and `should be separated from thecoolingA fluid.; By virtue of the structureshown in FigsjQ and l0 thisresult isalso achieved;-

In accordance with the provisions of the patent statutes, I have hereindescribed the principle of operation of my invention, to-; gether withthe apparatuswhich I now consider to represent the best embodimentsthereof, but I desire tov have it understood that the apparatusdisclosed is only illustrative and the invention can be carried out byother means. Also, While itisdesigned to use the various features andelements in the combinations and relations described, some of these maybe altered andr others omitted, and some of the features of eachrmodification may be embodied in the otherwithoutinterfering With. themorer general results and effects outlined, and the invention extends tosuch use.

What I claiml is:

l. The method of cooling` the diffuser of an ejector which comprisescausing a ,flow of fluidin Contact with the exterior of the diffuser,and increasing the rvelocity of the fluid-adjacent the neck of thediuser.

2. rlhe method of cooling the diffuser of a Asteam actuated ejector vwhich comprises causing a flow of liquid in contact with: the exteriorofthe diffuser,` andfincreasing'- the velocity of the liquid adjacentthe neck of the diffuser.

3. An ejector comprising,` in-combination, a nozzle,:a chamber havingfanvinlet for the fluid to be entrained and into Which saidl nozzledischarges,y a` diffuser communicating with said chamber, meansA forcausing a flow of liquid inl contact With the exterior of said.diffuser, and means whereby vthe velocity of. thel fluid stream isincreased adjacent the neck portion of said diffuser.

4.1An ejector comprising, in combination,- a nozzle, a chamber having aninlet for the fluid to be' entrained'and into which said nozzledischarges, a diffuse-r communicating With said chamber,andmeanscomprising. a' converging-diverging sleeve surrounding said diffuser forcausing a flow of cooling fluid in contact With the exterior-of` saiddiffuser. l

5. An ejector comprising, in combination, a diffusera casing surroundingsaid diffuser and forming a cooling'chamber around the same andsubstantially sealed at its lower portion,.and means whereby a coolingliquid may be circulated through said chamber, said means comprising aninlet for the fluid and an voutlet located adjacent the upper end ofsaid diffuser. j

In testimony jWhereof I hereto affixmy signature.

ALBERT DELAS.

